Fuel preparation process

Abstract

A fuel is produced by cleaning coal using an oil as a cleaning medium whereby the sulfur content of the fuel is substantially reduced and the heat content per pound is substantially increased by the reduction of water and other non-combustibles. The process may be used to produce a coal-oil fuel directly.

I claim: 
     
       1. The method of producing a low-sulfur fuel consisting essentially of coal particles suspended in an oil comprising the steps of: a. introducing a mixture of coal particles, and undesired particles having a higher specific gravity than coal, into a concentrator;   b. introducing oil into the concentrator;   c. cleaning said mixture in the concentrator, using oil as the cleaning medium, by effecting settling of undesired particles; and   d. removing from the concentrator a suspension of coal particles in oil for use as a fuel.   
     
     
       2. The method according to claim 1 in which the oil is brought into contact with the coal in a heated condition. 
     
     
       3. The method according to claim 1 in which the oil is brought into contact with the coal at a temperature above the boiling point of water. 
     
     
       4. The method according to claim 1 including the steps of removing refuse from the concentrator, separating heavy components from lighter components of said refuse, burning the lighter components, and using the heat generated in the burning step to heat the oil prior to its being brought into contact with the coal. 
     
     
       5. The method according to claim 1 including the steps of removing refuse from the concentrator, separating heavy components from lighter components of said refuse, burning the lighter components, and using the heat generated in the burning step to heat the coal prior to its introduction into the concentrator. 
     
     
       6. The method of claim 1 including the steps of removing the undesired particles from the concentrator along with oil, separating the oil so removed from the undesired particles, and returning the oil to the concentrator for use as a cleaning medium. 
     
     
       7. The method of claim 1 in which the mixture of coal particles and undesired particles is comminuted in the presence of oil prior to introduction of the mixture into the concentrator. 
     
     
       8. The method according to claim 1 in which the concentrator is a hindered settling concentrator.